Currently nothing is done to incentivize people to stay Covid free.... just the fear ... but even that is not enough
Actually since the vast majority of people in the world is covid free, the opposite makes more sense: some sort of punishment for the ones getting sick.
Of course, such thing cannot be implemented.
Also going by your idea, people should be periodically tested in order to incentivize them and here's a big problem: if they would have funds to properly test everybody periodically, no other move would be necessary, since normally most people don't want to get sick.
PS. There was an idea on the news that US may incentivize people to get the vaccine. That's doable and in line with your proposal too.
Same here in my country wherein the government will incentivize people who can produce a vaccine. There is no other way than that program because what OP said will just worsen the situation as over spending and corruption will possibly happen instead of using the money to buy vaccines and other posible usage in a specific country.